1. Field of the Invention
This invention relates to a liquid crystal display apparatus where a plurality of liquid crystal panels driven by thin film transistors are connected.
2. Description of the Related Art
To realize a large-scale display in a liquid crystal display apparatus, a substrate, a main component of the display, wherein electrodes for pixels are formed on the surface thereof (the substrate being referred to as an electrode substrate hereinafter) is connected to other substrates, since the size of one electrode substrate is restricted to the scale of the manufacturing equipment.
FIGS. 1 and 2 illustrate respectively a cross section showing the structure of a conventional liquid crystal display apparatus with a large-scale display as disclosed in Japanese Patent Application Laid Open No. 61-254977 and a cross section showing the manufacturing method of the apparatus, wherein an electrode substrate is designated by numeral 1. FIG. 3 is a partial wiring diagram of the electrode substrate 1. As is indicated in FIG. 3, switching active trasistors, namely, TFT's (Thin Film Transistor) 4 are arranged on the surface of the electrode substrate 1 so as to drive a liquid crystal at a position corresponding to each pixel. On the surface of the electrode substrate 1, a data bus line 2 is connected to a source of the TFT 4 and a gate bus line 3 orthogonal to the data bus line 2 is connected to a gate of the TFT 4. Referring back to FIGS. 1 and 2, two electrode substrates 1 are bonded by adhesives 5, and the respective data bus lines 2 and gate bus lines 3 are electrically connected with each other by a conductive thin film 6 formed through irradiation of laser beams 11. A counter electrode substrate 7 is provided above the electrode substrate 1 spaced by a spacer 8, with a liquid crystal 9 filled in between the electrode substrate 1 and counter electrode substrate 7. The liquid crystal 9 is prevented from leaking by sealing members 10.
A method to constitute a liquid crystal display apparatus with four connected electrode substrates 1 of the above-described structure will be discussed hereinafter. In the first place, four electrode substrates 1 are brought in touch with each other in a manner such that each electrode substrate 1 is in contact with the other substrates 1 on two sides. Then, the adhesives 5 are filled into the contacting parts of the electrode substrates 1 to connect the four electrode substrates 1. The bonded electrode substrate 1 is put in a reaction container containing a photo-reactive gas. Laser beams 11 are sequentially irradiated to the connecting points of the data bus lines 2 and gate bus lines 3, thereby forming the conductive thin films 6, respectively, to electrically connect the electrode substrates 1. Thereafter, the counter electrode substrate 7 is layered on the bonded electrode substrate 1 with a spacer 8 therebetween, and the liquid crystal 9 is filled in between the electrode substrates 1 and counter electrode substrate 7. The liquid crystal 9 is sealed by the sealing members 10. As a result, a liquid crystal display apparatus consisting of the four electrode substrates is obtained.
Although the foregoing description is directed to the liquid crystal display apparatus with four electrode substrates, a larger-scale display can be realized if more electrode substrates are connected in the above-described fashion.
However, since it is required to electrically connect the data bus lines and gate bus lines of the adjacent electrode substrates one by one in the conventional liquid crystal display apparatus, the problem of low productivity remains to be solved.